﻿// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
// 
// Copyright (c) 2014, Dr. Masroor Ehsan
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//    * Redistributions of source code must retain the above copyright
//      notice, this list of conditions and the following disclaimer.
//    * Redistributions in binary form must reproduce the above copyright
//      notice, this list of conditions and the following disclaimer in the
//      documentation and/or other materials provided with the distribution.
//    * Neither the name of the <organization> nor the
//      names of its contributors may be used to endorse or promote products
//      derived from this software without specific prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
// DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// 
// $Id$
// 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

using System.Collections.Generic;
using System.Text.RegularExpressions;
using Common.Logging;

namespace dseScraper
{
    internal class SanitizeHtml
    {
        private readonly Dictionary<string, Regex> _tidyPatterns = new Dictionary<string, Regex>();

        public SanitizeHtml()
        {
            _tidyPatterns = new Dictionary<string, Regex>
                            {
                                {@" ", new Regex(@"[\r\n]", RegexOptions.Compiled)},
                                {
                                    @"<body>",
                                    new Regex(@"<body[^>]*>", RegexOptions.Compiled | RegexOptions.IgnoreCase)
                                },
                                {@"<tr>", new Regex(@"<tr[^>]*>", RegexOptions.Compiled | RegexOptions.IgnoreCase)},
                                {@"<td>", new Regex(@"<td[^>]*>", RegexOptions.Compiled | RegexOptions.IgnoreCase)},
                                {
                                    @"<a href='#'>",
                                    new Regex(@"<a\s+href=[^>]*>", RegexOptions.Compiled | RegexOptions.IgnoreCase)
                                },
                                {
                                    @"<font>",
                                    new Regex(@"<font[^>]*>", RegexOptions.Compiled | RegexOptions.IgnoreCase)
                                },
                                {
                                    @"<!-- link -->",
                                    new Regex(@"<link[^>]*>", RegexOptions.Compiled | RegexOptions.IgnoreCase)
                                },
                                {
                                    @"<!-- meta -->",
                                    new Regex(@"<meta[^>]*>", RegexOptions.Compiled | RegexOptions.IgnoreCase)
                                }
                            };
        }

        public string Execute(string html)
        {
            if (string.IsNullOrEmpty(html))
            {
                var log = LogManager.GetLogger(GetType());
                log.Warn("Empty HTML given");
                return string.Empty;
            }

            foreach (var kv in _tidyPatterns)
            {
                html = kv.Value.Replace(html, kv.Key);
            }

            return "<html>" + html + "</html>";
        }
    }
}